Needle core biopsy and open biopsy of breast lesions: Comparison of histologic results and expression of hormone receptors and Ki-67

Purpose: To compare histologic findings and immunohistochemical staining fo r steroid hormone receptors and the nuclear proliferation Ki-67 in needle c ore biopsies and specimens subsequently obtained at open breast biopsy. Material and Methods: 58 patients underwent ultrasound-guided percutaneous needle biopsy of breast lesions. 48 lesions were subsequently excised. Expr ession of hormone receptors was evaluated immunohistochemically by the numb er and staining intensity of cells (n = 35). Ki-67 expression was assessed semiquantitatively on the basis of the number of positive cells (n = 14). Results: 48 core biopsie specimens were diagnosed as carcinoma and 8 as ben ign lesions. One biopsy contained no tissue and another showed epithelial c ells without nuclei; at open biopsy both these lesions were carcinomas. No complications occurred. Hormone receptor status was compared in 35 cases. A ll but estrogen-receptor-positive surgical specimens were associated with p ositive biopsy specimens, except one technically inadequate biopsy (97%). P rogesterone receptor status agreed in 31 cases (89%). Two biopsy specimens were technically inadequate. Two biopsies were negative while the surgical specimens were positive. One tumor showed homogenous but weak expression wh ereas the other showed heterogenous expression. Ki-67 activity was analyzed in 14 cases and agreed in 13 (98%). Conclusions: Ultrasound-guided needle core biopsy is an accurate technique for evaluating breast lesions. In breast carcinomas, hormone receptor statu s and Ki-67 expression can be assessed with a high degree of accuracy.